London/Singapore | British Prime Minister Boris Johnson has reintroduced compulsory mask-wearing in shops and on transport, plus COVID-19 tests with self-isolation for all overseas arrivals, after two cases of the omicron variant were detected in England.

Mr Johnson’s government will also try to get 6 million booster doses into English arms in the next three weeks, as his scientists scramble to work out how likely it is that the new Africa-origin variant, also known as B.1.1.529, can evade vaccine protection.